Page 259 - Fair, Geyer, and Okun's Water and wastewater engineering : water supply and wastewater removal

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6.8 Management, Operation, and Maintenance of Distribution Systems 219
6.8.1 General Maintenance Person Asphyxiated While Attempting to Repair Water Leak

The victim worked as a general maintenance person for a construction company, which
employed 13 persons. The construction company provided construction-related mainte-
nance for a local chain of restaurants. A supervisor for the construction company in-
structed a maintenance person (the victim) to inspect and repair a leaking water valve. The
water valve (a screw handle type) controlled the flow of water from the municipal water
system to a local restaurant. After the supervisor instructed the victim, he then left the site
of the restaurant to check on another job.
Apparently the victim proceeded to the fiberglass water meter pit (14 in. in diameter
by 4 ft deep or 350-mm diameter by 1.22 m deep) approximately 25 ft (7.62 m) from the
side of the restaurant where the water valve was located. The water meter pit was buried in
the ground and the top of the pit was at ground level. A metal cap was attached to the rim
of the water meter pit and a water meter with an in-line shutoff valve. A screw handle
water valve and the municipal water line were located in the pit. The valves were approxi-
mately 36 in. (914 mm) below the top of the pit (or ground level). The victim removed the
metal cap covering the pit and placed the cap on the ground next to the pit opening. He
then knelt beside the opening on both knees and reached into the pit until his head, both
arms, and part of his shoulders were inside the water meter pit. Apparently, the victim be-
came stuck upside down in the opening and could not free himself, causing asphyxiation
due to positional deprivation of air.
Recommendation #1: Supervisory personnel should routinely monitor employee perform-
ance to determine if employees have impaired physical and mental capabilities, which may be
related to the use of alcohol, illegal or over-the-counter drugs, or prescription medications.
Recommendation #2: Supervisory personnel should identify, evaluate, and address all
possible hazards associated with the job site. When employees are expected to work alone
at job sites, the area should first be evaluated and all possible hazards identified and ad-
dressed by supervisory personnel. The location of the water valve inside the water meter
pit required the use of extension tools, thereby eliminating the need to enter the water
meter pit (even partially).

6.8.2 Plumber Repairing a Water Line Killed When Struck by a Backhoe Bucket
A 47-year-old male plumber died when he was struck by the bucket of a backhoe while he was
repairing a water line in a trench for a shopping center. The victim and an apprentice plumber
were at the bottom of the trench removing straight and angled cast-iron pipes and placing them
in the backhoe bucket. The operator of the backhoe was an employee of the shopping center.
The operator told the police investigator that when he released all controls, the bucket swerved
to the left striking the victim on his left side and pinning him against the trench wall
A trench had to be excavated to reach the pipe. The trench was an oblong shape meas-
uring approximately 31 ft (9.45 m) long. One end was about 5 ft (1.52 m) wide and the other
end, where the incident occurred, was approximately 12 ft (3.66 m) wide. The trench depth
was 6 ft (1.83 m) at the edges going down to 7 ft (2.13 m) where the pipe was located. About
6 to 8 in. (150 to 200 mm) of water was on the bottom of the trench (see Fig. 6.18). There
was no shoring, shielding, or sloping of the trench walls.
An employee (hereinafter referred to as “operator”) of the shopping center operated the
backhoe to dig the trench. He had been with the firm for approximately 13 years and was in
charge of the safety of personnel, property, and the public for the mall. He had training on oper-
ating backhoes prior to employment with the firm and had operated the same model of backhoe
on jobs at the shopping center with the plumbing contractor. However, operating a backhoe was
not part of his regular duties. The operator had requested this particular model of backhoe be